Your soul existed before your birth, your soul will exist after your death.

Before the 3rd century you're having several philosophical schools still as a going concern. You have not only the Platonists and the Aristotelians but you have Scepticism, you have Stoicism, you even have a little bit of Epicureanism. And what happens after Plotinus is that everybody becomes a Neo-Platonist. So if we then go forward to the Islamic world for example, Plotinus is immensely influential, and Neo-Platonism becomes at least one major component of mainstream Islamic philosophy as well.

The forms in intellect are some kind of blueprint or model on which the physical world is based, and something needs to come along and shape the matter in accordance with that blueprint. What does that is soul.

In fact Plotinus does believe in divine providence, though when he talks about divine providence, he talks about that providence being exercised by the intellect and the soul of the world, rather than the One.

There's a stronger and more kind of controversial element of Plotinus' view of matter, which is that he actually identifies it with evil, or at least the principle of evil, and the reason for this is that he thinks that the the One, the highest principle, can also be thought of as the Good, and that's kind of surprising like, because he has this negative theology which doesn't allow us to say anything about the One. But he believes that it can be seen as the principle of goodness as well as unity, and that if you think about it, goodness and unity sort of go along with each other.

This is in a way the most important thing about soul is that it's a kind of principle which mediates between the universal intellect and the material world.

Plotinus is usually called the Founder of Neo Platonism and what that means is that in this philosophical circle, he was founding a kind of renewed attempt to understand the thought of Plato which however they were combining with the thought of other philosophers, including Aristotle, the Stoics and Pythagoreans and so on.